Add this to your Cargo.toml:
[dependencies]
bit-vec = "0.8"Since Rust 2018, extern crate is no longer mandatory. If your edition is old (Rust 2015),
add this to your crate root:
extern crate bit_vec;If you want serde support, include the feature like this:
[dependencies]
bit-vec = { version = "0.8", features = ["serde"] }If you want to use bit-vec in a program that has #![no_std], just drop default features:
[dependencies]
bit-vec = { version = "0.8", default-features = false }If you want to use serde with the alloc crate instead of std, just use the serde_no_std feature:
[dependencies]
bit-vec = { version = "0.8", default-features = false, features = ["serde", "serde_no_std"] }If you want borsh-rs support, include it like this:
[dependencies]
bit-vec = { version = "0.8", features = ["borsh"] }Other available serialization libraries can be enabled with the
miniserde and
nanoserde features.
Dynamic collections implemented with compact bit vectors.
This is a simple example of the Sieve of Eratosthenes which calculates prime numbers up to a given limit.
use bit_vec::BitVec;
let max_prime = 10000;
// Store the primes as a BitVec
let primes = {
// Assume all numbers are prime to begin, and then we
// cross off non-primes progressively
let mut bv = BitVec::from_elem(max_prime, true);
// Neither 0 nor 1 are prime
bv.set(0, false);
bv.set(1, false);
for i in 2.. 1 + (max_prime as f64).sqrt() as usize {
// if i is a prime
if bv[i] {
// Mark all multiples of i as non-prime (any multiples below i * i
// will have been marked as non-prime previously)
for j in i.. {
if i * j >= max_prime {
break;
}
bv.set(i * j, false)
}
}
}
bv
};
// Simple primality tests below our max bound
let print_primes = 20;
print!("The primes below {} are: ", print_primes);
for x in 0..print_primes {
if primes.get(x).unwrap_or(false) {
print!("{} ", x);
}
}
println!();
let num_primes = primes.iter().filter(|x| *x).count();
println!("There are {} primes below {}", num_primes, max_prime);
assert_eq!(num_primes, 1_229);Dual-licensed for compatibility with the Rust project.
Licensed under the Apache License Version 2.0: http://www.apache.org/licenses/LICENSE-2.0, or the MIT license: http://opensource.org/licenses/MIT, at your option.
